Sorry if the question is stupid, I haven't used Pi-hole before, so I'm curious what is the benefit of using it standalone or using it together with a DNS resolver like Unbound.
Filtering and logging. We filter from either public adlists to which you subscribe, or from local domain entries that are unique to your installation. When you subscribe to public adlists, we automatically pull in the domains (and update them weekly), so you don't have to have a script which fetches them.
We also provide history and statistics for DNS traffic through various logs and dashboard displays.
We also provide group management, so you can tailor your filtering for different client groups.